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Background: The output of many healthy physiological systems displays fractal fluctuations with self-similar temporal structures. Altered fractal patterns are associated with pathological conditions. There is evidence that patients with bipolar disorder have altered daily behaviors., Methods: To test whether fractal patterns in motor activity are altered in patients with bipolar disorder, we analyzed 2-week actigraphy data collected from 106 patients with bipolar disorder type I in a euthymic state, 73 unaffected siblings of patients, and 76 controls. To examine the link between fractal patterns and symptoms, we analyzed 180-day actigraphy and mood symptom data that were simultaneously collected from 14 patients., Results: Compared to controls, patients showed excessive regularity in motor activity fluctuations at small time scales (<1.5 h) as quantified by a larger scaling exponent (α1 > 1), indicating a more rigid motor control system. α1 values of siblings were between those of patients and controls. Further examinations revealed that the group differences in α1 were only significant in females. Sex also affected the group differences in fractal patterns at larger time scales (>2 h) as quantified by scaling exponent α2. Specifically, female patients and siblings had a smaller α2 compared to female controls, indicating more random activity fluctuations; while male patients had a larger α2 compared to male controls. Interestingly, a higher weekly depression score was associated with a lower α1 in the subsequent week., Conclusions: Our results show sex- and scale-dependent alterations in fractal activity regulation in patients with bipolar disorder. The mechanisms underlying the alterations are yet to be determined.

Background: In a large and comprehensively assessed sample of patients with bipolar disorder type I (BDI), we investigated the prevalence of psychotic features and their relationship with life course, demographic, clinical, and cognitive characteristics. We hypothesized that groups of psychotic symptoms (Schneiderian, mood incongruent, thought disorder, delusions, and hallucinations) have distinct relations to risk factors., Methods: In a cross-sectional study of 1342 BDI patients, comprehensive demographical and clinical characteristics were assessed using the Structured Clinical Interview for DSM-IV (SCID-I) interview. In addition, levels of childhood maltreatment and intelligence quotient (IQ) were assessed. The relationships between these characteristics and psychotic symptoms were analyzed using multiple general linear models., Results: A lifetime history of psychotic symptoms was present in 73.8% of BDI patients and included delusions in 68.9% of patients and hallucinations in 42.6%. Patients with psychotic symptoms showed a significant younger age of disease onset (β = -0.09, t = -3.38, p = 0.001) and a higher number of hospitalizations for manic episodes (F11 338 = 56.53, p < 0.001). Total IQ was comparable between groups. Patients with hallucinations had significant higher levels of childhood maltreatment (β = 0.09, t = 3.04, p = 0.002)., Conclusions: In this large cohort of BDI patients, the vast majority of patients had experienced psychotic symptoms. Psychotic symptoms in BDI were associated with an earlier disease onset and more frequent hospitalizations particularly for manic episodes. The study emphasizes the strength of the relation between childhood maltreatment and hallucinations but did not identify distinct subgroups based on psychotic features and instead reported of a large heterogeneity of psychotic symptoms in BD.

Objective: To investigate the prevalence of adolescent sleep disturbances and their relation to psychosocial difficulties and health risk behaviors with the use of data from a province-wide health survey (n = 16,781)., Methods: Psychosocial difficulties were measured with the Strength and Difficulties Questionnaire. Additional assessments included self-reported sleep disturbances, suicidality, and health risk behaviors including current use of tobacco, alcohol, and drugs, physical inactivity, and compulsive use of multimedia. We used multilevel analyses to investigate the relationhips, including differences, between boys and girls, as well as the mediating role of emotional problems., Results: Just under 20% of adolescents reported sleep disturbances in the previous month. These sleep disturbances were associated with psychosocial problems (odds ratio [OR], 6.42; P < .001), suicidality (OR, 3.90-4.14; P < .001), and all health risk behaviors (OR, 1.62-2.66; P < .001), but not with physical inactivity. We found moderation by gender for the relations between sleep and suicide attempts (OR, 0.38; P < .002) and between sleep and cannabis use (OR, 0.52; P = .002), indicating attenuated relationships in girls compared with boys. Emotional problems partially mediated the relationships between sleep disturbances and multimedia use., Conclusions: This study reiterates the high prevalence of sleep disturbances during adolescence. These sleep disturbances were strongly related to psychosocial problems and a wide range of health risk behaviors. Although the direction of causality cannot be inferred, this study emphasizes the need for awareness of impaired sleep in adolescents. Moreover, the gender differences in associated suicide attempts and cannabis use call for further research into tailored intervention strategies., (Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)